A technology developed by Oak Ridge National Laboratory works to keep food refrigerated with phase change materials, or PCMs, while reducing carbon emissions by 30%.
More than 100 million household refrigerators in operation across the United States consume up to 2 kilowatts of electricity daily. These refrigerators contribute to energy consumption and carbon emissions by using compressors that cycle on and off day and night, pumping refrigerants across evaporator coils to maintain low-temperatures for fresh and frozen compartments.
ORNL's innovation uses advanced evaporators with PCMs installed in each compartment for cold energy storage. PCMs are useful for heating and cooling because they store and release energy when changing from solids to liquids or vice versa. Researchers applied porous metals, direct-contact defrosting technology and a refrigerant with low global warming potential to enhance performance and minimize environmental impact.
"PCMs are integrated with evaporator coils to keep temperature constant, requiring one operating cycle and allowing refrigerators to operate almost 100% at nighttime, when energy use is lower," ORNL's Zhiming Gao said. "This reduces electricity demand, saves costs and maintains efficiency."
